Synopsis The RCD Method is a new method that has been developed to aim rationalization of concrete dam construction. Placing the concrete with very dry consistency and of lean-mixed by using generally damp trucks and bulldozers, the efficiency of the placement remarkably rises so that the construction period is shortened and safety is incresed. This paper describes mix proportion, quality control and characties of the concrete and the construction system in Tamagawa Dam Project adapting the method for a fast time as a large dam construction.